The application relates to nonaqueous electrolytes, nonaqueous electrolyte secondary batteries, and nonaqueous electrolyte secondary battery manufacturing methods. Specifically, the application relates to a nonaqueous electrolyte composition disposed in contact with at least one of a positive electrode and a negative electrode, and that includes a nonaqueous solvent, an electrolyte salt, a matrix polymer, and a ceramic powder, and to a nonaqueous electrolyte secondary battery.
With the advent of various portable electronic devices, there have been efforts to reduce the size and weight of the devices. This trend is also seen in batteries used as the power supply of portable electronic devices, requiring the size of the battery itself to be reduced, or the storage space in portable electronic devices to be used more efficiently for further reduction in the size and weight of the portable electronic devices. Lithium ion secondary batteries that have large energy density are known to be most desirable for meeting such demands.
Lithium ion secondary batteries are lightweight and have high energy density, and can thus be fabricated into very thin batteries. Because of these and other advantages, for example, those using a laminate film for the exterior member have already put to practical applications. For purposes relating to the prevention of leaking, such batteries using a laminate film for the exterior member use an electrolytic solution as an electrolyte, and a matrix polymer provided to hold the electrolytic solution. This type of battery is known as a polymer battery.
While the polymer battery offers great freedom in terms of shape because of the aluminum laminate film used for the exterior member, the battery may lack sufficient strength, and tends to undergo deformation under strong force that may be applied by wrong use of the battery. This is not problematic as long as the battery is packed in a strong exterior package. However, the recent demand for larger capacity has forced the use of simple exterior packages, increasing the chance for greater deformation, and the likelihood of shorting in the battery, with the result that the battery function may be lost.
As a countermeasure against such problems, batteries have been proposed that use ceramics applied to the electrode surface, as described in, for example, JP-A-10-214640 (Patent Document 1).